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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Uma variação do protocolo DCCP para redes de alta velocidade / A DCCP variation for high speed networks

Froldi, Carlos Augusto, 1979- 11 November 2011 (has links)
Orientador: Nelson Luis Saldanha da Fonseca / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-19T17:25:04Z (GMT). No. of bitstreams: 1 Froldi_CarlosAugusto_M.pdf: 543951 bytes, checksum: e4f64a2921c88fd1461445bd39a04278 (MD5) Previous issue date: 2011 / Resumo: Os protocolos da camada de transporte na Internet, TCP e UDP, não oferecem serviços para transmissão eficiente de fluxos multimídia, porém, este último é adotado com maior freqüência por essas aplicações. Uma proposta de um novo protocolo da camada de transporte, chamado DCCP, foi elaborada para atender a demanda das aplicações multimídia e substituir o protocolo UDP. A presente dissertação propõe uma variante deste protocolo, chamada Fast DCCP, para operar de maneira eficiente em redes de alta velocidade. A nova variante foi avaliada através de experimentos de simulação, utilizando o NS-2 e experimentos de medição, utilizando o sistema operacional Linux / Abstract: The Internet transport layer protocols, TCP and UDP, do not provide efficient transport service for multimedia streams. UDP is usually used for these applications, due to its low overhead. A new transport layer protocol, called DCCP, was proposed to meet the demand of multimedia applications, aiming at replacing the UDP protocol. This dissertation will propose a variant for this protocol, called Fast DCCP, for operating efficiently on high-speed networks. It was evaluated by simulation using the NS-2 network simulator and measurements of the FAST DCCP protocol operation in the Linux operating system / Mestrado / Ciência da Computação / Mestre em Ciência da Computação
12

Filtros digitais para recepção coerente em 112 Gb/s de sinais ópticos com modulação QPSK e multiplexação por divisão em polarização / Digital filters for optical signal coherent reception at 112 Gbit /s by using QPSK modulation and polarization division multiplexing

Ribeiro, Vitor Bedotti 22 August 2018 (has links)
Orientadores: Aldário Chrestani Bordonalli, Júlio César Rodrigues Fernandes de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-22T02:02:14Z (GMT). No. of bitstreams: 1 Ribeiro_VitorBedotti_M.pdf: 8224184 bytes, checksum: f63b4dc7f1e4170cdcb48f49bf1b4155 (MD5) Previous issue date: 2012 / Resumo: As mudanças nos padrões de tráfego na internet forçam a constante evolução das redes ópticas, que, por serem sistemas com grande capacidade e se estenderam por milhares de quilômetros, são a principal aposta para suprir a demanda por banda. A solução adotada foi aumentar a eficiência espectral da transmissão, por meio do uso de formatos de modulação de alta ordem, como o PSK e o QAM, da detecção coerente e da multiplexação em polarização. Nessa dissertação, os conceitos de uma transmissão coerente digital e os principais algoritmos para a recepção e recuperação de sinal são apresentados, considerando o formato de modulação DP-QPSK com taxa agregada de 112 Gb/s. É proposto, também, um método de adaptação de ganho para o algoritmo de módulo constante (CMA), que acelera a convergência e torna a rotina que rastreia as mudanças no estado de polarização do sinal óptico mais rápido e robusto. Os algoritmos para cada funcionalidade foram testados individualmente em simulação. O melhor conjunto de algoritmos é analisado e configurações experimentais em back-to-back com carregamento de ruído ASE, em anel de recirculação óptico de 225 km com 80 canais DWDM e, também, em transmissão pela Rede Experimental de Alta Velocidade GIGA no trecho Campinas - São Paulo - Campinas. Para a configuração em back-to-back, o limite do sistema foi de 10,5 dB de OSNR. No anel de recirculação, foi possível a transmissão de 80 canais a 112 Gb/s, totalizando 8,96 Tbit/s por 2925 km e ocupando 50 GHz de banda, ou por 2475 km e ocupando 25 GHz. Na rede GIGA, o sistema se mostrou estável, com taxa de erro de bits bem inferior ao limite por mais de 3 horas de análise. O método de adaptação de ganho proposto conseguiu acompanhar mais de 20 Mrad/s e 3 Mrad/s de variação angular no estado de polarização para 34 dB e 15 dB de OSNR, respectivamente, enquanto o CMA sem adaptação de ganho falha a 10 Mrad/s e 1,5 Mrad/s nas mesmas condições. Os resultados demonstram a eficácia e a estabilidade dos algoritmos e a capacidade de recuperação do sinal em simulação, em experimentos laboratoriais ou em campo / Abstract: The changes in traffic patterns due to the Internet force the constant evolution of optical networks. These systems, designed to deliver high transmission capacity over thousands of kilometers, are the key solution to meet the demand for bandwidth. The recent tendency to provide wider bandwidth without changing the infrastructure already deployed has been to increase the spectral efficiency of transmission by using high order modulation formats, such as PSK and QAM, and employment coherent detection along with polarization multiplexing. In this work the concepts of optical digital coherent systems and the main algorithms for signal reception and recovery are presented, considering QPSK modulation format and polarization multiplexing (DP-QPSK) at 112 Gb/s. It is also proposed a method for adaptive adjustment of the constant modulus algorithm (CMA) gain, which accelerates the convergence and makes the algorithm faster and more robust to changes in the state of polarization of the optical signal. The algorithms for each function were tested individually in a simulation setup. The best set of algorithms were then obtained and applied in the receiver end of different experimental setups: back-to-back with ASE noise loading; 225-km optical recirculation loop with 80 DWDM channels; and a field transmission over part of the high-capacity experimental network GIGA (Campinas - São Paulo - Campinas). For the back-to-back setup, the system limit was achieved at 10.5 dB of OSNR. For the recirculation loop, it was possible to transmit up to 80 channels at 112 Gb/s, or 8.96 Tbit/s for overall system capacity, over 2925 km, considering 50-GHz bandwidth signal, or 2475 km for 25-GHz bandwidth signal. For the GIGA network, the system was stable with bit error rate well below the FEC threshold during the 3-hour analysis. The gain adaptation method proposed was able to track over 20 Mrad/s and 3 Mrad/s of angular rotation rate in the state of polarization for OSNRs of 34 dB and 15 dB, respectively, while the CMA without gain adaptation fails to track frequencies above 10 Mrad/s and 1.5 Mrad/s in the same conditions. The results show that the set of algorithms is effective, stable and capable of recovering the signal during simulation, laboratory experiments or field trials / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
13

Vysokorychlostní sítě v domácnosti / High-speed Networks in Household

Rosenberg, Michal January 2012 (has links)
The master thesis discusses about the relation between high-speed networks and intelligent system installation features and possibilities of this mutual interaction. Furthermore principles of KNX bus tunneling through IP networks are theoretically analyzed (KNXnet/IP). Practical use of implements KNXnet/IP shows real elements on the test panel. The control is realized by KNX@Home in the Ubuntu environment. Simulation of the real state tunneling KNX bus represent model in Opnet Modeler, which shows how the delays may change due to network load.
14

Rychlé zpracování aplikačních protokolů / Fast Processing of Application-Layer Protocols

Bárta, Stanislav January 2014 (has links)
This master's thesis describes the design and implementation of system for processing application protocols in high-speed networks using the concept of Software Defined Monitoring. The proposed solution benefits from hardware accelerated network card performing pre-processing of network traffic based on the feedback from monitoring applications. The proposed system performs pre-processing and filtering of network traffic which is handed afterwards passed to application modules. Application modules process application protocols and generate metadata that describe network traffic. Pre-processing consists of parsing of network protocols up to the transport layer, TCP reassembling and forwarding packet flow only to modules that are looking for a given network traffic. The proposed system closely links intercept related information internal interception function (IRI-IIF) and content of communication internal interception function (CC-IIF) to minimize the performing of duplicate operations and increase the efficiency of the system.
15

Hardwarová akcelerace aplikací pro monitorování a bezpečnost vysokorychlostních sítí / Hardware Acceleration of Network Security and Monitoring Applications

Kekely, Lukáš January 2013 (has links)
This master's thesis deals with the design of software controlled hardware acceleration system for high-speed networks. The main goal is to provide easy access to acceleration for various network security and monitoring applications. The proposed system is designed for 100 Gbps networks. It enables high-speed processing on an FPGA card together with flexible software control. The combination of hardware speed and software flexibility allows easy creation of complex high-performance network applications.  Achievable performance improvement of three chosen monitoring and security applications is shown using simulation model of the designed system.
16

Filtrace paketů ve 100 Gb sítích / Packet Filtration in 100 Gb Networks

Kučera, Jan January 2016 (has links)
This master's thesis deals with the design and implementation of an algorithm for high-speed network packet filtering. The main goal was to provide hardware architecture, which would support large rule sets and could be used in 100 Gbps networks. The system has been designed with respect to the implementation on an FPGA card and time-space complexity trade-off. Properties of the system have been evaluated using various available rule sets. Due to the highly optimized and deep pipelined architecture it was possible to reach high working frequency (above 220 MHz) together with considerable memory reduction (on average about 72% for compared algorithms). It is also possible to efficiently store up to five thousands of filtering rules on an FPGA with only 8% of on-chip memory utilization. The architecture allows high-speed network packet filtering at wire-speed of 100 Gbps.
17

Softwarově řízené monitorování síťového provozu / Software-Controlled Network Traffic Monitoring

Kekely, Lukáš January 2017 (has links)
Tato disertační práce se zabývá návrhem nového způsobu softwarově řízené (definované) hardwarové akcelerace pro moderní vysokorychlostní počítačové sítě. Hlavním cílem práce je formulace obecného, flexibilního a jednoduše použitelného konceptu akcelerace použitelného pro různé bezpečnostní a monitorovací aplikace, který by umožnil jejich reálné nasazení ve 100 Gb/s a rychlejších sítích. Disertační práce začíná rozborem aktuálního stavu poznání v oborech síťového monitorování, bezpečnosti a způsobů akcelerace zpracování vysokorychlostních síťových dat. Na základě tohoto rozboru je formulován a navržen zcela nový koncept s názvem Softwarově definované monitorování (SDM). Klíčová funkcionalita uvedeného konceptu je postavená na hardwarově akcelerované, aplikačně specifické (řízené), na tocích založené, informované redukci a distribuci zachycených síťových dat. Toto je zajištěno spojením vysokorychlostního hardwarového zpracování s flexibilním softwarovým řízením, které tak společně umožňují jednoduchou tvorbu různých komplexních a vysoce výkonných síťových aplikací. Pokročilé optimalizace a vylepšení základního SDM konceptu a jeho vybraných komponent jsou v práci též zkoumány, což vede k návrhu zcela unikátní a obecně použitelné FPGA architektury modulárního analyzátoru hlaviček paketů a vysoce výkonného klasifikátoru paketů založeného na kukaččím hashovaní. Nakonec je vytvořen vysokorychlostní SDM prototyp postavený nad FPGA akcelerační síťovou kartou, který je podrobně ověřen v podmínkách nasazení do reálných sítí. Jsou změřeny a diskutovány dosažitelné zlepšení výkonností v několika vybraných monitorovacích a bezpečnostních případech užití. Vytvořený SDM prototyp je rovněž nasazen v produkčním monitorování reálné páteřní sítě sdružení Cesnet a byl komercializován společností Netcope Technologies.
18

[en] MULTICAST COMMUNICATION IN OPTICAL IP INTERNETWORKS / [pt] DIFUSÃO SELETIVA EM INTER-REDES IP BASEADAS EM REDES ÓPTICAS

ANTONIO JORGE GOMES ABELEM 12 September 2003 (has links)
[pt] A difusão seletiva e os recentes avanços na tecnologia de transmissão óptica, mais especificamente na multiplexação por comprimento de onda (Wavelength Division Multiplexing- WDM), aliados à consolidação do IP como protocolo dominante das redes convergentes, vêm oferecendo novas perspectivas para as futuras gerações de inter-redes. Este trabalho faz uso da evolução dessas tecnologias para propor um conjunto de adaptações à difusão seletiva, em especial ao IP Multicast, denominado MIRROR (Multicast IP para Redes baseadas em Rajadas Ópticas Rotuladas). A proposta MIRROR sugere modificações e adequações para tornar o IP Multicast menos complexo, mais escalável em relação ao número de grupos ativos simultaneamente e mais adequado às redes baseadas em comutação óptica. Basicamente, MIRROR revê a necessidade de todos os roteadores ao longo da árvore de distribuição multiponto manterem informações de estado relacionadas a esta, bem como sugere adequações na forma como os caminhos multiponto são estabelecidos quando se emprega comutação baseada em rótulos na difusão seletiva. Para avaliar a proposta MIRROR, investiu-se em duas frentes distintas, uma baseada na análise comparativa entre a MIRROR e algumas alternativas ao IP Multicast apresentadas na literatura, e outra baseada no desenvolvimento de um protótipo da proposta no simulador NS (Network Simulator), com o intuito de referendar os resultados da análise comparativa. Na análise comparativa, confronta-se parâmetros como: requisitos de informações de estado, custo com informações de controle, custo de encaminhamento dos pacotes e custo da árvore de multiponto. O desenvolvimento do protótipo envolveu a criação de uma nova estrutura de nó e a alteração de módulos já existentes no NS, para tornar possível a simulação de redes comutadas por rajadas ópticas rotuladas no contexto da difusão seletiva. / [en] Multicast communication and recent advances in optical technology, most specifically in Wavelength Division Multiplexing (WDM), allied with the consolidation of IP as the dominant protocol of convergent networks, offer new perspectives for the next generation Internet. This thesis utilises these technologies to propose a set of adaptations, called MIRROR, to multicast communication, specifically IP Multicast, in labelled burst-switched optical networks. MIRROR proposes modifications to traditional IP Multicast in order to improve its scalability as a function of the number of simultaneously active groups, as well as making it more appropriate for use in optically switched networks. Basically, MIRROR includes new proposals for handling state information about the multicast distribution tree, as well as for the establishment of label-based multicast paths. In order to evaluate this proposal, two approaches are followed, one based on a comparative analysis between MIRROR and a number of other alternatives to IP Multicast proposed in the literature, and the other based on the implementation of a prototype in the simulation environment provided by NS (Network Simulator). The comparative analysis evaluates such parameters as: state requirement information, control overhead, packet processing efficiency and tree cost. The prototype implementation implements a new node structure and alters existing NS modules (OBS e MPLS), to make possible the simulation of labelled burst-switched optical networks in the multicast context.
19

Rozšíření aplikace DPDK DNS Probe / The DPDK DNS Probe Application Extension

Doležal, Pavel January 2019 (has links)
This master's thesis is focused on extension of the DPDK DNS Probe application that monitors DNS traffic in high speed networks. It presents framework DPDK, which can be used for fast packet processing. General architecture of the DNS system is described as well as details of its components. Basic principles of transport protocol TCP are described. It introduces an effective design and implementation of DNS packet parsing to optimize DPDK DNS Probe's performance. It also introduces a design and implementation of processing DNS messages sent over TCP for export of traffic statistics. The application's performance was tested using a high speed traffic generator Spirent.
20

Využití jazyka P4 k popisu akcelerovaného zařízení na ochranu před DoS útoky / P4 Language-Based Description of Accelerated Device against DoS Attacks

Kuka, Mário January 2019 (has links)
This thesis describes the development of a networking device used to defend against (D)DoS attacks using P4 language. The main purpose was to design flexible device using P4 lan-guage based on already existing device, this would allow us to quickly react and respond to new more complex DDoS attacks. The design of the device dealt with the transfer of individual parts of the firmware into the P4 language. Subsequently, the entire device firmware was designed for hardware accelerators with FPGA technology. The firmware had been designed with respect to the limitations of current P4 language compilers. The device has been tested under laboratory conditions for functionality and performance. The device will be deployed in the network infrastructure of CESNET.

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